Good evening and thank you for the opportunity to help in answering your question. I typically don't answer questions of this nature but I felt a pull to answer it for you. Although this is not my primary area of expertise I am certainly knowledgeable about dream interpretation.
Based on the information you've provided about your brother, the timing of the dream as well as as the feelings that pulled you to your father's home my conclusions are kind of unusual and are based on a great deal of research that I have done on my own in the field of paranormal activity and it's relation to psychology.
The theory goes that if the deceased individual comes to you in a dream and that you are capable of recalling each specific detail and that they speak to you with you in a manner that is consistent with their passing...basically meaning that they are aware of their being deceased then it's thought to be a "visit."
If most parts of what I mentioned are not consistent with the dream itself then it is nothing more than your subconscious seeping through and the fact that it was his birthday that likely prompted the dream.
I hardly ever do this...but I am citing this answer from both a PERSONAL as well as a professional knowledge of dreams about deceased relatives and the interactions had with them during the course of the dream.
I will of course leave up to you about accepting the answer or not...I just hope that this helps you with gaining a better understanding of the potential of the dream.
Please let me know if you have any further questions or thoughts. Thank you for the chance to help.